Add @recast-navigation/playcanvas package

[isaac-mason]

No description provided.

[marklundin]

Hey @isaac-mason just checking if you need anything more from me on this. Happy to jump in to help move things forward :D

[isaac-mason]

Hey @marklundin, I think this branch is just about ready to merge and get out there!

It would be great if you could take a look at the standalone playcanvas example I added, as well as take a look at changes I made to @recast-navigation/playcanvas. I'm not deeply familiar with playcanvas so let me know if I should revert/amend any of the changes I made.

You can see the standalone playcanvas example I added here: https://github.com/isaac-mason/recast-navigation-js/pull/438/files#diff-6eb676771678639035973890d1cfb6f747c48365ce2f343f6500725f77be662a
It would be good to extend it to use more/all of the helpers in @recast-navigation/playcanvas too, so we can easily test for regressions in this repo.

The main changes I made to @recast-navigation/playcanvas are:

• removing the need to pass a graphics device to the generator helpers eg pcToSoloNavMesh
• moving common debug draw utils into the core library
• prettier blast and small refactors